Valve with self-contained stem centering device



April 7, 1953 w. E. Jol-msv 2,634,085

vALvE WITH SELF-CONTAINED STEM CENTERING DEVICE Filed Aug. 15, 195o 2SHEETS- SHEET 1 L@ zz/gffedyw April 7. 1953 w. E. JOHNS 2,634,086

VALVE WITH SELF-CONTAINED STEM CENTERING DEVICE Filed Aug. 15, 1950 2SHEETS-SHEET 2 l INVENTOR.

Patented Apr. 7, 4 1953 VALVE WITH SELF-CONTAINED STEM CENTERING DEVICEWilfred E. Johns, Rockford, Ill., assignor to Sundstrand Machine ToolCo., a corporation of Illinois Application August 15, 1950, Serial No.179,568

7 Claims.

provide a new, improved and more accurate centeringdevice for valveassemblies.

Another object of this invention is to provide a spool type valve havinga hollow core, plungers lextending out through openings in each end oithe core and having means to limit their outward movement, means formoving thevalve .to the right or left of a normal position, and a coilspring compressed between'said plungers and operating to bias them intoextended position, the plungers in their extended position serving tocenter the valve. V

.v A further object of this invention is to provide a new and improvedvalve centering device which is operated with a single spring so thatspring fatigue will have substantially no effect on the accuracy ofcentering of the valve. Regardless of the fatigue in a single spring,the pressure it exerts inV opposite directions remains the same.

A further object of this invention is to provide a unitaryself-centering valve which may be rinserted or removed from a valve bodyin one piece.

Further objects will be readily apparent from the following detaileddescription read in conjunction with the accompanying drawings, wherein:Y Fig. l is a sectional view of a valve mechanism embodying a preferredform of the invention;

Fig. 2 is a sectional View of the valve assembly Vtaken substantiallyalong the line 2-2 of Fig. 1;

Fig. 3 is a sectional view of the valve assembly takensubstantiallyalong the line 3 3 of Fig. 2;

Fig. 4 is a sectional view taken along the line ,ll-4 of Fig. 2;

Fig. 5 is a sectional view taken substantially along the line 5-5 ofFig. 3; and Fig. 6 is a detailed view of the actuating plunger formoving the valve. Y

While this invention is susceptible of embodiment in many diierentforms, there is shown in the drawings and will herein be described indetailone specific embodiment, with the understanding that `the presentdisclosure is to be considered as an exemplication of the principles ofthe' invention and is not intended to limit the invention to theembodiment illustrated. The scope of the invention will be pointed outin theappended claims. I

Referring now to Fig. `1 of the drawings, there is shown a pilot valve 2connected to a main valve 3 with the latter being adapted t0 be actuatedby pilot pressure delivered from the pilot valve.

The pilot valve 2 comprises a spool valve 4 slidable in a cylindricalbore 5 extending through a casing S. The spool valve is provided with apair of reduced portions 7 adapted to communicate with a plurality ofgrooves 8 extending around the bore 5, which grooves are to be suppliedwith pilot fluid under pressure.

As best shown in Figs. 2 and 3, the pilot valve 4 is provided with ahollow core 9 which extends from end to end of the valve. Extendingthrough the core is a rod I threaded at each end to a plunger II whichextends outwardly through holes I2 provided in end plates I3 which closeeach end of thebore 5. The plungers II are slidably mounted in aU-shaped slot I4 provided at the outer ends of stop members' I5, onestop member being locatedat each end of the bore. The outer ends of thestop members bear against the end plates I3 and the inner ends of thestop members bear against a compression spring I6 which surrounds therod I0. The plungers il 4are provided with beveled portions I1 which arepress fitted into correspondingly beveled portions I8 lat the outer endsof the spool valve 4. Each of the plungers II is provided with athreaded extension I9 extending through an opening 20 in the inner endsof the stop members and adapted to be threaded into the ends of the rodID. Thus the plungers II areV secured 'to therod III and to the spoolvalve 4 and are movable inwardly and outwardly in the U -shaped slotsI4. Y

The outer ends of the spool valve 4 are provided with annular grooves2l, in each of which is seated a sealingring 22 in order to preventleakage of uid from the outer ends of the bore 5.

In the specific embodiment chosen for illustration, the means for movingthe plungers inwardly and outwardly comprises solenoids 23 located ateach end of the pilot valve 2 with each of the solenoids being providedwith an armature 24 connected to the plungers II.

With energization of one of the solenoids, ior example the left-handsolenoid shownin Fig. 1, the armature 24 associated therewith is movedto the rightv moving the left-most plunger II to the right. Rightwardmovement of that plunger brings its inner end into contact with theleft-most stop member I5 to move that mem ber to the rightcompressingthe spring I5. Inasmuch as the plunger is secured to the spool valvethat member is also moved to the right to direct hydraulic iluid to oneor the other ends of the mainvalve 3. Rightward movement of theright-handstop member I5 is prevented because of the engagement of theouter ends thereof with the right-hand end plate I3. With deenergizationof` the solenoid, the compression spring I6 serves to move the stopmember to the left, which movement carries theplunger I I along with itand the latter member by reason of its connection with the 4spool valveserves to center the valve and bring it to 01T or central p osition.Similarly energization of the right-hand end serves to move the pilotvalve to the left in a manner similar to that just described.

I claim:

1. A self-centering valve comprising a casing having a bore, a valvemember having a hollow core and slidable within the bore, a stop memberat each end of the core, each of the stop members having one endextending slidably into the core and having the other .end abuttingagainst a member fixed to the casing, aplunger secured to each end ofthe valve member and movable longitudinally of the bore, a rod extendingthroughthe Vcore and connected to each o f the plungers, a vcompressionspring surrounding the rod and having its ends bearing against the innerends of the stop members and means o n each plunger adapted to contacttheadjacent stop member to move such stop member inwardly along with thevalve member with inward movement of the plunger whereby to compress thespringagainst the opposite stop member to bias the valve member towardreturn movement.

2. A self-centering valve comprising a casing having a bore, a valvemember having a hollow core and slidable within the bore, a stopmemberat each end of the core, each of the stop members having one endextending slidably into the core with the other end of the stop memberbeing slotted and abutting against a member xed to the casing, a plungersecured to each end ,of the valve member and movable longitudinally ofthe bore in said slots, a rod extending through the core and connectedto each of the plungers, a compression spring surrounding the rod andhaving its ends bearing against the inner ends of the stop members andmeans on each plunger adapted to contact the adjacent stop member tomove such stop member inwardly along with the valve member with inwardmovement vof the plunger whereby to compress the spring against theopposite stop member to bias the valve member toward return movement.

3. A self-centering valve comprising a casing having a bore, a valvemember having a hollow core and slidable within the bore, a stop memberat each end of the core, each of the stop members having one endextending slidably into the core with the other en d of the stop memberbeing slotted and abutting against a member fixed to the easing, a vplunger press tted inte each end I" the valve member .and movablelongitudinally of the bore in said slots, a rod extending through thecore and connected to each of; the plungers, a compression springsurrounding the Vrod and having its ends bearing against the inner endsof the Sten members and means en eeen plunger adapted te Contact theadjacent-stop member to move Such Step member inwardly along with theValve member with inward movement ef the plunger whereby i0 COmplzeSSthe Spring against the Opposite step member te bias the valve membertoward return movement..

4- A Self-@entering valve eomnrisinga casing having a bore! a ValVemember slidable Within the bore and provided with a hollow core, aplunger at one end of the bore and secured tothe valve member, a stopmember slidable in the core and positioned to be contacted by theplunger With inward movement thereof to be moved therewith, a singlecompression spring extending longitudinally of the core, and stop meansin the bore supporting one end of the spring, with the other end of thespring bearing against the stop member, whereby inward movement of theplunger moves the valve member in the bore and compresses said springbetween the stop means and the stop member tobias the valve membertoward return movement.

5. A selfcentering valve comprising a casing having a bore, a valvemember having a hollow core and slidable iin the bore, a stop member ateach end of the core, each of said stop members having an inner portionslidable within the core and an outer portion abutting against thecasing, a compression spring in the core and extending between andcontacting the inner portions of the stop members, an actuating memberextending -through the stop members and through the core, said actuatingmember being secured to the valve member and provided adjacent each endwith a portion adapted to contact the stop member at that end uponinward movement of the actuating member to move the stop membertherewith and means for moving the actuating member longitudinally ofthe core.

6. A self-centering valve comprising a casing having a bore, a valvemember having a hollow core and slidable in the bore, a stop member ateach end of the core, each of the stop members having an inner portionslidable Within the core and an outer portion, a compression spring inthe core and extending between and bearing against the inner portions ofthe stop members to press said outer portions of the stop membersoutwardly against the casing, oppositely facing actuating memberssecured to the valve member at each end of the core and adapted to movethe adjacent stop` member inwardly along with the valve member withmovement thereof whereby to compress the spring against the oppositestop member to bias the valve member toward return movement.

'7. A self-centering valve comprising a casing having a bore, a valvemember having a hollow core and slidable in the bore, a stop member ateach end of the core, each of the stop members having an inner portionslidable within the core and an outer portion, a compression spring inthe core and extending between and bearing against the inner portions ofthe stop members to press said outer portions of the stop membersoutwardly against the casing, an actuating member secured to the valvemember and adapted to move one of thestop members inwardly along withthe valve member with movement of the valve member in one direction andto move the other stop member inwardly along with the valve member withmovement of the valve member in the other direction wherebyin eithercase to compress the spring against the unmoved stop member to bias thevalve member toward return movement.

WILFRED E. JOHNS.

REFERENCES CITED The. following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,145,977 Foster Feb. '7, 19392,238,768 Berglund Apr. 15, 1941 2,404,349 Brandt July 23, 194s`

